An Afghan Taliban delegation has arrived in Pakistan to meet officials in a bid to restart a stuttering peace process with Kabul, Afghan officials and Taliban leaders said on Tuesday, although it was unclear who the delegation was meeting.

There was no immediate confirmation from authorities in Pakistan but just a week after a massive bomb blast in Kabul killed at least 64 people and wounded hundreds, the Afghan government refused to take part.

Last month, the Taliban ruled out participating in what it called "futile" talks sponsored by the four-power group of Pakistan, Afghanistan, the United States and China as long as foreign forces remain in the country.

In Kabul, the Afghan government has been frustrated by what it sees as Islamabad's refusal to honor a pledge to force Taliban leaders based in Pakistan to join the talks, or face military action.

"We are aware that Taliban delegations are in Pakistan, but we will not go there until Pakistan fulfils the promises that they made," said Dawa Khan Mina Pal, a spokesman for Afghan president Ashraf Ghani.

On Monday, Ghani said the opportunity for peace talks "will not be there forever" and urged Pakistan to fight Taliban groups on its soil that rejected peace.

Afghanistan has long accused Pakistan of actively harboring the Afghan Taliban leadership on its soil, a charge Islamabad denies, saying it only has "limited influence".

A senior Taliban member based in Pakistan confirmed that a delegation of leaders was in the southern port city of Karachi, holding talks with Pakistani officials.

"They arrived on Monday," he said, speaking on condition of anonymity, because the Taliban leadership has not authorized him to discuss the talks with the media. "They left for an unknown location later in the day and returned late at night."

Two members of the Taliban's political office in the Gulf state of Qatar, which has played a role in previous attempted peace talks, confirmed the delegation's presence in Pakistan, but indicated meetings were being held in the capital, Islamabad.

"Our people held a meeting with Pakistani officials and I am sure they may meet the Chinese on Tuesday," said one of the Qatar-based leaders, speaking on condition of anonymity, also because he is not authorized to discuss the talks.

"We don't care if Kabul participates in the meeting, as we already launched our spring offensive and are getting successes against them," he said.

The Pakistani Foreign Office and the Afghan embassy in Islamabad did not immediately respond to requests for comment.

Taliban spokesman Zabihullah Mujahid said he was not authorized to comment on the activities of the movement's Qatar political office.